Remove setVTable calls in performance critical areas

Remove setVTable calls in performance critical areas

Remove all the calls to setVTable that were in performance
critical parts of the code. This now brings performance
back to the level we had with the vtable inlined in the
Managed objects.

Change-Id: I76317cc5c53b5b700d1d3883b954407142a4c424
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>